Conventionally, an example of a target of biometrics authentication includes blood vessels. As a related art of such a technique, an authentication device which extracts, as feature points, end points and branch points of blood vessels shown in a captured image and generates data of a registration target or data for comparison with the registration target using the extracted feature points has been proposed (refer to Patent Document 1, for example). In this authentication device, an amount of usage of a memory for storage can be considerably reduced when compared with a case where image data is directly registered.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2003-303178
However, since the end points and the branch points are discretely distributed in the blood vessels, they have less reliability as elements to be used to discriminate a registrant. Accordingly, even if a method for generating a feature point as data of a comparison target is the same as a method for generating a feature point as data of a registration target, there arises a problem in that it is highly possible that an error is made in a determination such that a third party is determined as a certain person or a certain person is determined as a different person due to an external factor such as an environment of imaging operation or noise, or an internal factor such as difficulty of imaging of blood vessels in a live body (which is different between individuals), that is, authentication accuracy (accuracy of discrimination of a registrant) is poor.